Absorbent structures with high absorbency and low basis weight

ABSTRACT

Absorbent product including a laminate of at least two plies, wherein the absorbent product has a measured Valley Volume parameter greater than 11 microns and a Pit Density of greater than 25 pockets per sq. cm.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/798,606, filed Feb. 24, 2020 and entitled ABSORBENT STRUCTURES WITHHIGH ABSORBENCY AND LOW BASIS WEIGHT, issued as U.S. Pat. No.11,098,453, which in turn claims priority to and the benefit of U.S.Provisional Application No. 62/842,629, filed May 3, 2019 and entitledABSORBENT STRUCTURES WITH HIGH ABSORBENCY AND LOW BASIS WEIGHT, thecontents of these applications being incorporated herein by reference intheir entirety.

FIELD OF THE INVENTION

The present invention relates to absorbent structures, in particular todisposable paper towels or wipes, with unique surface topography thatresults in a product with high absorbency at lower levels of basisweight than comparable absorbent structures.

BACKGROUND

Across the globe there is great demand for disposable, absorbentstructures used for household cleaning tasks. Disposable towels andwipes meet this market demand. Disposable paper towels and wipes thatare composed of cellulosic based fibers are also nearly 100% renewableand biodegradable, thus catering to those whom are eco-conscience. Thesedisposable absorbent towels and wipes are used for a multitude of tasksthat require absorbency and strength. These tasks include absorbingliquid spills, cleaning windows and mirrors, scrubbing countertops andfloors, scrubbing and drying dishes, washing/cleaning bathroom sinks andtoilets, and even drying/cleaning hands and faces where the attribute ofsoftness becomes important. A disposable towel or wipe that can performthese demanding tasks and be produced at a price point that provides avalue proposition to the consumer is advantageous. To maintain a lowprice point, as well as conserve cellulosic based natural resources,providing for high strength and absorbency using the least amount ofmaterial is advantageous.

The industrial methods or technologies used to produce these absorbentstructures are numerous. Absorbent structures can be produced using bothWater or Air-Laid technologies. The technologies that use water to formthe cellulosic (or other natural or synthetic fiber type) webs thatcomprises the towel or wipe are called Water-Laid Technologies. Theseinclude Through Air Drying (TAD), Uncreped Through Air Drying (UCTAD),Conventional Wet Crepe (CWC), Conventional Dry Crepe (CDC), ATMOS, NTT,ETAD, and QRT. Technologies that use air to form the webs that comprisethe towel or wipe are called Air-Laid Technologies. To enhance thestrength and absorbency of these towels and wipes, more than one layerof web (or ply) can be laminated together using strictly a mechanicalprocess or preferably a mechanical process that utilizes an adhesive.

The Water-Laid technologies of Conventional Dry and Wet Crepe are thepredominant method to make these structures. These methods compriseforming a nascent web in a forming structure, transferring the web to adewatering felt where it is pressed to remove moisture, and adhering theweb to a Yankee Dryer. The web is then dried and creped from the YankeeDryer and reeled. When creped at a solids content of less than 90%, theprocess is referred to as Conventional Wet Crepe. When creped at asolids content of greater than 90%, the process is referred to asConventional Dry Crepe. These processes can be further understood byreviewing Yankee Dryer and Drying, A TAPPI PRESS Anthology, pg 215-219,which is herein incorporated by reference. These methods are wellunderstood and easy to operate at high speeds and production rates.Energy consumption per ton is low since nearly half of the water removedfrom the web is through drainage and mechanical pressing. Unfortunately,the sheet pressing also compacts the web, which lowers web thickness andresulting absorbency. A more detailed description of the ConventionalDry Crepe process follows.

The major steps of the conventional dry crepe process involve stockpreparation, forming, pressing, drying, creping, calendering (optional),and reeling the web.

The first step of stock preparation involves selection, blending,mixing, and preparation of the proper ratio of wood, plant, or syntheticfibers along with chemistry and fillers that are needed in the specifictissue grade. This mixture is diluted to over 99% water in order toallow for even fiber formation when deposited from the machine headboxinto the forming section. There are many types of forming sections usedin conventional papermaking (inclined suction breast roll, twin wireC-wrap, twin wire S-wrap, suction forming roll, and Crescent formers)but all are designed to retain the fiber, chemical, and filler recipewhile allowing the water to drain from the web. In order to accomplishthis, fabrics are utilized.

After web formation and drainage (to around 35% solids) in the formingsection (assisted by centripetal force around the forming roll, andvacuum boxes in several former types), the web is transferred to a pressfabric upon which the web is pressed between a rubber or polyurethanecovered suction pressure roll and Yankee dryer. The press fabric is apermeable fabric designed to uptake water from the web as the web ispressed in the press section. The press fabric is composed of largemonofilaments or multi-filamentous yarns, needled with fine syntheticbatt fibers to form a smooth surface for even web pressing against theYankee dryer. Removing water via pressing results in low energyconsumption.

After pressing the sheet between a suction pressure roll and a steamheated cylinder (referred to as a Yankee dryer), the web is dried fromup to 50% solids to up to 99% solids using the steam heated cylinder andhot air impingement from an air system (air cap or hood) installed overthe steam cylinder. The sheet is then creped from the steam cylinderusing a steel or ceramic doctor blade. This is a critical step in theconventional dry crepe process. The creping process greatly affectssoftness as the surface topography is dominated by the number andcoarseness of the crepe bars (finer crepe is much smoother than coarsecrepe). Some thickness and flexibility is also generated during thecreping process. If the process is a wet crepe process, the web must beconveyed between dryer fabrics through steam heated after-dryer cans todry the web to the required finished moisture content. After creping,the web is optionally calendered and reeled into a parent roll and readyfor the converting process.

The absorbency of a conventional tissue web is low due to the web beingpressed. This results in a low bulk, low void volume web where there islittle space for water to be absorbed. Additionally, bulk generated bycrepeing is lost when the web is wetted, further reducing bulk and voidvolume.

The through air drying (TAD) process is another manufacturing method formaking a tissue web. The major steps of the through air drying processare stock preparation, forming, imprinting, thermal pre-drying, drying,creping, calendering (optional), and reeling the web. The stockpreparation and forming steps are similar to conventional dry creping.

Rather than pressing and compacting the web, as is performed inconventional dry crepe, the web in the TAD process undergoes the stepsof imprinting and thermal pre-drying. Imprinting is a step in theprocess where the web is transferred from a forming fabric to astructured fabric (or imprinting fabric) and subsequently pulled intothe structured fabric using vacuum (referred to as imprinting ormolding). This step imprints the weave pattern (or knuckle pattern) ofthe structured fabric into the web. This imprinting step has atremendous effect on the softness of the web, both affecting smoothnessand the bulk structure. The design parameters of the structured fabric(weave pattern, mesh, count, warp and weft monofilament diameters,caliper, air permeability, and optional over-laid polymer) are,therefore, important to the development of web softness. Themanufacturing method of an imprinting/structuring fabric is similar to aforming fabric (see U.S. Pat. Nos. 3,473,576; 3,573,164; 3,905,863;3,974,025; and 4,191,609 for examples) except for an additional step ifan overlaid polymer is utilized. These types of fabrics are disclosedin, for example, U.S. Pat. Nos. 6,120,642 5,679,222; 4,514,345;5,334,289; 4,528,239; and 4,637,859. Essentially, fabrics produced usingthese methods result in a fabric with a patterned resin applied over awoven substrate. The benefit is that resulting patterns are not limitedby a woven structure and can be created in any desired shape to enable ahigher level of control of the web structure and topography that dictateweb quality properties.

After imprinting, the web is thermally pre-dried by moving hot airthrough the web while it is conveyed on the structured fabric. Thermalpre-drying can be used to dry the web to over 90% solids before it istransferred to a steam heated cylinder. The web is then transferred fromthe structured fabric to the steam heated cylinder though a very lowintensity nip (up to 10 times less than a conventional press nip)between a solid pressure roll and the steam heated cylinder. The onlyportions of the web that are pressed between the pressure roll and steamcylinder rest on knuckles of the structured fabric, thereby protectingmost of the web from the light compaction that occurs in this nip. Thesteam cylinder and an optional air cap system, for impinging hot air,then dry the sheet to up to 99% solids during the drying stage beforecreping occurs. The creping step of the process again only affects theknuckle sections of the web that are in contact with the steam cylindersurface. Due to only the knuckles of the web being creped, along withthe dominant surface topography being generated by the structuredfabric, and the higher thickness of the TAD web, the creping process hasmuch smaller effect on overall softness as compared to conventional drycrepe. After creping, the web is optionally calendered and reeled into aparent roll and ready for the converting process. Some TAD machinesutilize fabrics (similar to dryer fabrics) to support the sheet from thecrepe blade to the reel drum to aid in sheet stability and productivity.Creped through air dried products are disclosed in, for example, U.S.Pat. Nos. 3,994,771; 4,102,737; 4,529,480; and 5,510,002.

The TAD process is generally higher in capital costs than a conventionaltissue machine due to the amount of air handling equipment needed forthe TAD section with higher energy consumption from burning natural gasor other fuels for thermal pre-drying. The bulk softness and absorbencyis superior to conventional paper due to the superior bulk generationvia structured fabrics which creates a low density, high void volume webthat retains its bulk when wetted. The surface smoothness of a TAD webcan approach that of a conventional tissue web. The productivity of aTAD machine is less than that of a conventional tissue machine due tothe complexity of the process and especially the difficulty in providinga robust and stable coating package on the Yankee dryer needed fortransfer and creping of a delicate pre-dried web.

A variation of the TAD process where the sheet is not creped, but ratherdried to up to 99% using thermal drying and blown off the structuredfabric (using air) to be optionally calendered and reeled also exits.This process is called UCTAD or un-creped through air drying process. Anuncreped through air dried product is disclosed in U.S. Pat. No.5,607,551.

A new process/method and paper machine system for producing tissue hasbeen developed by the Voith company and is being marketed under the nameATMOS. The process/method and paper machine system have several patentedvariations, but all involve the use of a structured fabric inconjunction with a belt press. The major steps of the ATMOS process andits variations are stock preparation, forming, imprinting, pressing(using a belt press), creping, calendering (optional), and reeling theweb.

The stock preparation step is the same as that used in a conventional orTAD machine. The purpose is to prepare the proper recipe of fibers,chemical polymers, and additives that are necessary for the grade oftissue being produced, and diluting this slurry to allow for proper webformation when deposited out of the machine headbox (single, double, ortriple layered) to the forming surface. The forming process can utilizea twin wire former (as described in U.S. Pat. No. 7,744,726) a CrescentFormer with a suction Forming Roll (as described in U.S. Pat. No.6,821,391), or preferably a Crescent Former (as described in U.S. Pat.No. 7,387,706). The preferred former is provided a slurry from theheadbox to a nip formed by a structured fabric (inner position/incontact with the forming roll) and forming fabric (outer position). Thefibers from the slurry are predominately collected in the valleys (orpockets, pillows) of the structured fabric and the web is dewateredthrough the forming fabric. This method for forming the web results in aunique bulk structure and surface topography as described in U.S. Pat.No. 7,387,706 (FIG. 1 through FIG. 11). The fabrics separate after theforming roll with the web staying in contact with the structured fabric.At this stage, the web is already imprinted by the structured fabric,but utilization of a vacuum box on the inside of the structured fabriccan facilitate further fiber penetration into the structured fabric anda deeper imprint.

The web is now transported on the structured fabric to a belt press. Thebelt press can have multiple configurations. The first patented beltpress configurations used in conjunction with a structured fabric can beviewed in U.S. Pat. No. 7,351,307 (FIG. 13), where the web is pressedagainst a dewatering fabric across a vacuum roll by an extended nip beltpress. The press dewaters the web while protecting the areas of thesheet within the structured fabric valleys from compaction. Moisture ispressed out of the web, through the dewatering fabric, and into thevacuum roll. The press belt is permeable and allows for air to passthrough the belt, web, and dewatering fabric, and into the vacuum roll,thereby enhancing the moisture removal. Since both the belt anddewatering fabric are permeable, a hot air hood can be placed inside ofthe belt press to further enhance moisture removal as shown in FIG. 14of U.S. Pat. No. 7,351,307. Alternately, the belt press can have apressing device arranged within the belt which includes several pressshoes, with individual actuators to control cross direction moistureprofile (see FIG. 28 of U.S. Pat. No. 7,951,269 or 8,118,979 or FIG. 20of U.S. Pat. No. 8,440,055) or a press roll (see FIG. 29 of U.S. Pat.No. 7,951,269 or 8,118,979 or FIG. 21 of U.S. Pat. No. 8,440,055). Thepreferred arrangement of the belt press has the web pressed against apermeable dewatering fabric across a vacuum roll by a permeable extendednip belt press. Inside the belt press is a hot air hood that includes asteam shower to enhance moisture removal. The hot air hood apparatusover the belt press can be made more energy efficient by reusing aportion of heated exhaust air from the Yankee air cap or recirculating aportion of the exhaust air from the hot air apparatus itself (see U.S.Pat. No. 8,196,314). Further embodiments of the drying system composedof the hot air apparatus and steam shower in the belt press section aredescribed in U.S. Pat. Nos. 8,402,673, 8,435,384 and 8,544,184.

After the belt press is a second press to nip the web between thestructured fabric and dewatering felt by one hard and one soft roll. Thepress roll under the dewatering fabric can be supplied with vacuum tofurther assist water removal. This preferred belt press arrangement isdescribed in U.S. Pat. Nos. 8,382,956, and 8,580,083, with FIG. 1showing the arrangement. Rather than sending the web through a secondpress after the belt press, the web can travel through a boost dryer(FIG. 15 of U.S. Pat. No. 7,387,706 or 7,351,307), a high pressurethrough air dryer (FIG. 16 of U.S. Pat. No. 7,387,706 or 7,351,307), atwo pass high pressure through air dryer (FIG. 17 of U.S. Pat. No.7,387,706 or 7,351,307) or a vacuum box with hot air supply hood (FIG. 2of U.S. Pat. No. 7,476,293). U.S. Pat. Nos. 7,510,631, 7,686,923,7,931,781 8,075,739, and 8,092,652 further describe methods and systemsfor using a belt press and structured fabric to make tissue productseach having variations in fabric designs, nip pressures, dwell times,etc. and are mentioned here for reference. A wire turning roll can alsobe utilized with vacuum before the sheet is transferred to a steamheated cylinder via a pressure roll nip (see FIG. 2a of U.S. Pat. No.7,476,293).

The sheet is now transferred to a steam heated cylinder via a presselement. The press element can be a through drilled (bored) pressureroll (FIG. 8 of U.S. Pat. No. 8,303,773), a through drilled (bored) andblind drilled (blind bored) pressure roll (FIG. 9 of U.S. Pat. No.8,303,773), or a shoe press (see U.S. Pat. No. 7,905,989). After the webleaves this press element to the steam heated cylinder, the % solids arein the range of 40-50% solids. The steam heated cylinder is coated withchemistry to aid in sticking the sheet to the cylinder at the presselement nip and to also aid in removal of the sheet at the doctor blade.The sheet is dried to up to 99% solids by the steam heated cylinder andinstalled hot air impingement hood over the cylinder. This dryingprocess, the coating of the cylinder with chemistry, and the removal ofthe web with doctoring is explained in U.S. Pat. Nos. 7,582,187 and7,905,989. The doctoring of the sheet off the Yankee, creping, issimilar to that of TAD with only the knuckle sections of the web beingcreped. Thus, the dominant surface topography is generated by thestructured fabric, with the creping process having a much smaller effecton overall softness as compared to conventional dry crepe. The web isthen calendered (optional,) slit, and reeled and ready for theconverting process.

The ATMOS process has capital costs between that of a conventionaltissue machine and TAD machine. It has more fabrics and a more complexdrying system compared to a conventional machine, but less equipmentthan a TAD machine. The energy costs are also between that of aconventional and TAD machine due to the energy efficient hot air hoodand belt press. The productivity of the ATMOS machine has been limiteddue to the ability of the novel belt press and hood to dewater the weband poor web transfer to the Yankee dryer, likely driven by poorsupported coating packages, the inability of the process to utilizestructured fabric release chemistry, and the inability to utilizeoverlaid fabrics to increase web contact area to the dryer. Pooradhesion of the web to the Yankee dryer has resulted in poor creping andstretch development which contributes to sheet handling issues in thereel section. The result is that the production of an ATMOS machine iscurrently below that of a conventional and TAD machine. The bulksoftness and absorbency is superior to conventional, but lower than aTAD web since some compaction of the sheet occurs within the belt press,especially areas of the web not protected within the pockets of thefabric. Also, bulk is limited since there is no speed differential tohelp drive the web into the structured fabric as exists on a TADmachine. This severely limits the ability to produce a bulky, absorbentpaper towel. The surface smoothness of an ATMOS web is between that of aTAD web and conventional web primarily due to the current limitation onuse of overlaid structured fabrics.

The ATMOS manufacturing technique is often described as a hybridtechnology because it utilizes a structured fabric like the TAD process,but also utilizes energy efficient means to dewater the sheet like theConventional Dry Crepe process. Other manufacturing techniques whichemploy the use of a structured fabric along with an energy efficientdewatering process are the ETAD process and NTT process.

The ETAD process and products can be viewed in U.S. Pat. Nos. 7,339,378,7,442,278, and 7,494,563. This process can utilize any type of formersuch as a Twin Wire Former or Crescent Former. After formation andinitial drainage in the forming section, the web is transferred to apress fabric where it is conveyed across a suction vacuum roll for waterremoval, increasing web solids up to 25%. Then the web travels into anip formed by a shoe press and backing/transfer roll for further waterremoval, increasing web solids up to 50%. At this nip, the web istransferred onto the transfer roll and then onto a structured fabric viaa nip formed by the transfer roll and a creping roll. At this transferpoint, speed differential can be utilized to facilitate fiberpenetration into the structured fabric and build web caliper. The webthen travels across a molding box to further enhance fiber penetrationif needed. The web is then transferred to a Yankee dryer where it can beoptionally dried with a hot air impingement hood, creped, calendared,and reeled.

The ETAD process to date has been reported to have severe productivity,quality, and cost problems. Poor energy efficiency has been reported,bulk has been difficult to generate (likely due to high web dryness atthe point of transfer to the structured fabric), and softness has beenpoor (coarse fabrics have been utilized to generate target bulk, therebydecreasing surface smoothness). Absorbency is better than ATMOS due tothe ability to utilize speed differential to build higher bulk, but itis still below that of TAD which can create higher bulk with limited webcompaction that would otherwise reduce void volume and thus absorbency.The installed costs of an ETAD machine are likely close to that of a TADmachine due to the large amount of fabrics and necessary supportingequipment.

The NTT process and products can be viewed in international patentapplication publication WO 2009/061079 A1, and U.S. Patent ApplicationPublication Nos. US 2011/0180223 A1 and US 2010/0065234 A1. The processhas several embodiments, but the key step is the pressing of the web ina nip formed between a structured fabric and press felt. The webcontacting surface of the structured fabric is a non-woven material witha three dimensional structured surface comprised of elevations anddepressions of a predetermined size and depth. As the web is passedthrough this nip, the web is formed into the depression of thestructured fabric since the press fabric is flexible and will reach downinto all of the depressions during the pressing process. When the feltreaches the bottom of the depression, hydraulic force is built up whichforces water from the web and into the press felt. To limit compactionof the web, the press rolls will have a long nip width which can beaccomplished if one of the rolls is a shoe press. After pressing, theweb travels with the structured fabric to a nip with the Yankee dryer,where the sheet is optionally dried with a hot air impingement hood,creped, calendared, and reeled.

The NTT process has low capital costs, equal or slightly higher than aconventional tissue machine. It has high production rates (equal orslightly less than a conventional machine) due to the simplicity ofdesign, the high degree of dewatering of the web at the shoe press, andthe novelty of construction of the structured fabric. The structuredfabric, which will be described later in this document, provides asmooth surface with high contact area to the dryer for efficient webtransfer. This high contact area and smooth surface makes the Yankeecoating package much easier to manage and creates conditions beneficialfor fine creping, resulting in good sheet handling in the reel section.The bulk softness of the NTT web is not equal to the ATMOS sheet as theweb is highly compacted inside the structured fabric by the press feltcompared to the ATMOS web. The surface smoothness is better than anATMOS web due to the structured fabric design providing for bettercreping conditions. The NTT process also does not have a speeddifferential into the structured fabric so the bulk and absorbencyremains below the potential of the TAD and ETAD processes.

The QRT process is disclosed in US 2008/0156450 A1 and U.S. Pat. No.7,811,418. The process can utilize a twin wire former to form the webwhich is then transferred to a press fabric or directly formed onto apress fabric using an inverted Crescent former. The web can be dewateredacross a suction turning roll in the press section before being pressedin an extended nip between the press fabric and a plain transfer belt. Arush transfer nip is utilized to transfer the web to a structured fabricin order to build bulk and mold the web before the web is transferred tothe Yankee dryer and creped. This process alleviates the NTT designdeficiency which lacks a rush transfer or speed differential to forcethe web into the structured fabric to build bulk. However, the costs,complexity, and likely productivity will be negatively affected.

Absorbent structures are also made using the Air-Laid process. Thisprocess spreads the cellulosic, or other natural or synthetic fibers, inan air stream that is directed onto a moving belt. These fibers collecttogether to form a web that can be thermally bonded or spray bonded withresin and cured. Compared to Wet-Laid, the web is thicker, softer, moreabsorbent and also stronger. It is known for having a textile-likesurface and drape. Spun-Laid is a variation of the Air-Laid process,which produces the web in one continuous process where plastic fibers(polyester or polypropylene) are spun (melted, extruded, and blown) andthen directly spread into a web in one continuous process. Thistechnique has gained popularity as it can generate faster belt speedsand reduce costs.

To further enhance the strength of the absorbent structure, more thanone layer of web (or ply) can be laminated together using strictly amechanical process or preferably a mechanical process that utilizes anadhesive. It is generally understood that a multi-ply structure can havean absorbent capacity greater than the sum of the absorbent capacitiesof the individual single plies. Without being bound by theory, it isthought this difference is due to the inter-ply storage space created bythe addition of an extra ply. When producing multi-ply absorbentstructures, it is important that the plies are bonded together in amanner that will hold up when subjected to the forces encountered whenthe structure is used by the consumer. Scrubbing tasks such as cleaningcountertops, dishes, and windows all impart forces upon the structurewhich can cause the structure to rupture and tear. When the bondingbetween plies fails, the plies move against each other, therebyimparting frictional forces at the ply interface. This frictional forceat the ply interface can induce failure (rupture or tearing) of thestructure, thus reducing the overall effectiveness of the product toperform scrubbing and cleaning tasks.

There are many methods used to join or laminate multiple plies of anabsorbent structure to produce a multi-ply absorbent structure. Onemethod commonly used is embossing. Embossing is typically performed byone of three processes: tip to tip (or knob to knob), nested, or rubberto steel DEKO embossing. Tip to tip embossing is illustrated by commonlyassigned U.S. Pat. No. 3,414,459, while nested embossing process isillustrated in U.S. Pat. No. 3,556,907. Rubber to steel DEKO embossingcomprises a steel roll with embossing tips opposed to a pressure roll,sometimes referred to as a backside impression roll, having anelastomeric roll cover wherein the two rolls are axially parallel andjuxtaposed to form a nip where the embossing tips of the emboss rollmesh with the elastomeric roll cover of the opposing roll through whichone sheet passes and a second unembossed sheet is laminated to theembossed sheet using a marrying roll nipped to the steel embossing roll.In an exemplary rubber to steel embossing process, an adhesiveapplicator roll may be aligned in an axially parallel arrangement withthe patterned embossing roll, such that the adhesive applicator roll isupstream of the nip formed between the emboss and pressure roll. Theadhesive applicator roll transfers adhesive to the embossed web on theembossing roll at the crests of the embossing knobs. The crests of theembossing knobs typically do not touch the perimeter of the opposingidler roll at the nip formed therebetween, necessitating the addition ofa marrying roll to apply pressure for lamination.

Other attempts to laminate absorbent structure webs include bonding theplies at junction lines wherein the lines include individual pressurespot bonds. The spot bonds are formed using thermoplastic low viscosityliquid such as melted wax, paraffin, or hot melt adhesive, as describedin U.S. Pat. No. 4,770,920. Another method laminates webs of absorbentstructure by thermally bonding the webs together using polypropylenemelt blown fibers as described in U.S. Pat. No. 4,885,202. Other methodsuse meltblown adhesive applied to one face of an absorbent structure webin a spiral pattern, a stripe pattern, or a random pattern beforepressing the web against the face of a second absorbent structure asdescribed in U.S. Pat. Nos. 3,911,173, 4,098,632, 4,949,688, 4,891249,4,996,091 and 5,143,776.

The technologies described above enable the production of absorbentstructures with various attributes. With these technologies, higherabsorbency is generally tied to higher basis weight (more cellulosefibers in the product). There is a continuing need for improvedabsorbent structures that are cost effective and more absorbent.

SUMMMARY OF THE INVENTION

An object of this invention is to provide absorbent structures withpreviously unattainable levels of absorbency at low levels of basisweight.

An absorbent structure according to an exemplary embodiment of thepresent invention includes a laminate of at least two plies, wherein theabsorbent structure has a measured Valley Volume parameter greater than11 microns and a Pit Density of greater than 25.

An absorbent product according to an exemplary embodiment of the presentinvention includes a laminate of at least two plies, wherein theabsorbent product has an absorbency of greater than 16.0 grams of waterper gram of fiber and a basis weight of less than 43 grams per squaremeter.

Obtaining high levels of absorbency at low levels of basis weight allowsfor costs to be controlled by limiting the addition of costly fibrousmaterial to the product. Environmental benefits are also obtainedthrough conservation of natural resources that are needed to obtainfibrous material.

An absorbent product according to an exemplary embodiment of the presentinvention comprises a laminate of at least two plies, and the absorbentproduct has a measured Valley Volume parameter greater than 11 micronsand a Pit Density of greater than 25 pockets per sq. cm.

According to an exemplary embodiment, the absorbent product has anabsorbency of greater than 16.0 grams of water absorbed per gram ofabsorbent product.

According to an exemplary embodiment, the absorbent product has a basisweight of less than 43 grams per square meter.

According to an exemplary embodiment, the absorbent product is producedusing a wet laid structured tissue process.

According to an exemplary embodiment, at least one of the at least twoplies comprises cellulosic-based fibers.

According to an exemplary embodiment, the cellulosic-based fibers areselected from the group consisting of wood pulp, cannabis, cotton,regenerated or spun cellulose, jute, flax, ramie, bagasse, kenaf fibersand combinations thereof.

According to an exemplary embodiment, at least one of the at least twoplies comprises synthetic fibers.

According to an exemplary embodiment, the synthetic fibers are made froma polymer selected from the group consisting of polyolefin, polyester,polypropylene and polylactic acid.

According to an exemplary embodiment, at least one of the two pliescomprises synthetic fibers.

According to an exemplary embodiment, the synthetic fibers are made froma polymer selected from the group consisting of polyolefin, polyester,polypropylene and polylactic acid.

According to an exemplary embodiment, the absorbent product comprisesboth synthetic and cellulosic based polymers.

According to an exemplary embodiment, each of the at least two plies isembossed and the at least two plies are adhered together.

According to an exemplary embodiment, the at least two plies are adheredtogether with a water soluble adhesive mixture comprised of polyvinylalcohol, polyvinyl acetate, starch based resins or mixtures thereof.

According to an exemplary embodiment, the water soluble adhesive isapplied to at least one ply of the at least two plies at a temperaturewithin a range of 32 degrees C. to 66 degrees C.

According to an exemplary embodiment, the water soluble adhesive mixturefurther comprises a water soluble cationic resin selected from the groupconsisting of polyamide-epichlorohydrin resins, glyoxalatedpolyacrylamide resins, polyethyleneimine resins, polyethylenimineresins, and mixtures thereof.

According to an exemplary embodiment, each of the at least two pliescomprises an embossed area, wherein the embossed area occupies betweenapproximately 5 to 15% of the total surface area of a surface of theply.

According to an exemplary embodiment, each of the at least two pliescomprises an embossed area having a surface, wherein a depth ofembossment of the surface is between approximately 0.28 and 0.43centimeters.

According to an exemplary embodiment, each of the at least two pliescomprises an embossed area having a surface, wherein each embossment ofthe surface is between approximately 0.04 and 0.08 square centimeters insize.

According to an exemplary embodiment, the absorbent product is one of apaper towel, a disposable towel or wipe, a bath or facial tissue, or anonwoven product.

According to an exemplary embodiment, the absorbent product has anabsorbency of greater than 18.0 grams of water absorbed per gram ofabsorbent product.

According to an exemplary embodiment, the absorbent product has a basisweight of less than 40 grams per square meter.

According to an exemplary embodiment, the absorbent product has a basisweight of less than 51 grams per square meter.

A two-ply disposable towel according to an exemplary embodiment of thepresent invention has an absorbency greater than 18.0 grams of waterabsorbed per gram of towel.

An absorbent product according to an exemplary embodiment of the presentinvention comprises a laminate of at least two plies, wherein theabsorbent product has an absorbency of greater than 16.0 grams of waterabsorbed per gram of absorbent product and a basis weight of less than43 grams per square meter.

According to an exemplary embodiment, the absorbent product is a papertowel.

According to an exemplary embodiment, the absorbent product is tissuepaper.

A through-air-dried disposable towel product according to an exemplaryembodiment of the present invention comprises a laminate of at least twoplies, and the product has a measured Valley Volume parameter greaterthan 11 microns and a Pit Density of greater than 25 pockets per sq. cm.

According to an exemplary embodiment, the disposable towel product hasan absorbency of greater than 16.0 grams of water absorbed per gram ofproduct.

According to an exemplary embodiment, the disposable towel product has abasis weight of less than 43 grams per square meter.

According to an exemplary embodiment, the disposable towel product isproduced using a wet laid structured tissue process.

According to an exemplary embodiment, at least one of the at least twoplies comprises cellulosic-based fibers.

A disposable towel product according to an exemplary embodiment of thepresent invention comprises a laminate of at least two plies, whereinthe product has a measured Valley Volume parameter greater than 11microns and a Pit Density of greater than 25 pockets per sq. cm, andwherein the disposable towel is through-air-dried.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and related objects, features and advantages of the presentinvention, will be more fully understood by reference to the followingdetailed description of the exemplary embodiments of the presentinvention, when taken in conjunction with the following exemplaryfigures, wherein:

FIG. 1 is a block diagram illustrating a papermaking process accordingto an exemplary embodiment of the present invention;

FIG. 2 is a micrograph of a structuring fabric according to an exemplaryembodiment of the present invention;

FIG. 3 is a representative diagram of a creping stage of a conventionalpapermaking process;

FIG. 4 is a representative diagram of a creping stage of a papermakingprocess according to an exemplary embodiment of the present invention.

FIG. 5 is a representative diagram of an apparatus for manufacturing alaminate of two plies of a structured paper towel or tissue that arejoined to each other, in a face-to-face relationship, in accordance withan exemplary embodiment of the present invention;

FIG. 6 are various diagrams illustrating calculation of Valley Volume ina sample's 3D data set through the use of its material ratio curve;

FIG. 7 are various diagrams illustrating calculation of Pit Density;

FIG. 8 shows the Pre-processing settings used to calculate Valley Volumeand Pit Density in accordance with exemplary embodiment of the presentinvention.

FIG. 9 shows the Geometry Settings used to calculate Valley Volume andDensity in accordance with exemplary embodiments of the presentinvention;

FIG. 10 shows the Filtering settings used to calculate Valley Volume andPit Density in accordance with exemplary embodiments of the presentinvention;

FIG. 11 is a micrograph of a surface of a paper towel product made inaccordance with an exemplary embodiment of the present invention;

FIG. 12 is a table providing values for various surface parameters andphysical properties of a Comparative Example and various commerciallyavailable disposable towel products as compared to those of a productmade in accordance with an exemplary embodiment of the presentinvention; and

FIG. 13 illustrates a pattern of embossments formed on the surface of apaper towel product made in accordance with an exemplary embodiment ofthe present invention.

DETAILED DESCRIPTION

A laminate according to an exemplary embodiment of the present inventionis composed of two or more webs/plies of absorbent structures laminatedtogether in a face-to face relationship using a heated aqueous adhesive.The laminate exhibits previously unattainable levels of high absorbencyat particularly low basis weights. Each ply or a single ply may have aplurality of embossments protruding outwardly from the plane of the plytowards the adjacent ply. The adjacent ply likewise may have opposingprotuberances protruding towards the first ply. If a three ply productis produced, the central ply may have embossments extending outwardly inboth directions.

The absorbent structures can be manufactured by any Wet-Laid or Air-Laidmethods. The materials used to produce the disposable structured tissueor paper towel product can be fibers selected from cellulosic-basedfibers, such as wood pulps (softwood gymnosperms or hardwoodangiosperms), cannabis, cotton, regenerated or spun cellulose, jute,flax, ramie, bagasse, kenaf, or other plant based cellulosic fibersources in any ratio. Synthetic fibers, such as a polyolefin (e.g.,polypropylene), polyester, or polylactic acid can also be used. Each plyof a multi-ply absorbent product of the present invention may comprisecellulosic based fibers and/or synthetic fibers. Also, any of the pliesmay be layered with a different fiber composition in each layer. Such alayering of fibers can be produced using a multilayered headbox on a wetlaid asset such as a TAD paper machine.

FIG. 1 is a block diagram of a system for manufacturing a three-layeredply of an absorbent structure generally designated by reference number100, according to an exemplary embodiment of the present invention. Thesystem 100 includes a first exterior layer fan pump 102, a core layerfan pump 104, a second exterior layer fan pump 106, a headbox 108, aforming section 110, a drying section 112 and a calender section 114.The first and second exterior layer fan pumps 102, 106 deliver the pulpmixes of the first and second external layers 2, 4 to the headbox 108,and the core layer fan pump 104 delivers the pulp mix of the core layer3 to the headbox 108. As is known in the art, the headbox delivers a wetweb of pulp onto a forming wire within the forming section 110. The wetweb is then laid on the forming wire with the core layer 3 disposedbetween the first and second external layers 2, 4.

Wet end additives may be mixed with the pulp prior to delivery to theheadbox. To impart wet strength to the absorbent structure in the wetlaid process, typically a cationic strength component is added to thefurnish during stock preparation. The cationic strength component caninclude any polyethyleneimine, polyethylenimine,polyaminoamide-epihalohydrin (preferably epichlorohydrin),polyamine-epichlorohydrin, polyamide, or polyvinylamide wet strengthresin. Useful cationic thermosetting polyaminoamide-epihalohydrin andpolyamine-epichlorohydrin resins are disclosed in U.S. Pat. Nos.2,926,154, 3,049,469, 3,058,873, 3,066,066, 3,125,552, 3,186,900,3,197,427, 3,224,986, 3,224,990, 3,227,615, 3,240,664, 3,813,362,3,778,339, 3,733,290, 3,227,671, 3,239,491, 3,240,761, 3,248,280,3,250,664, 3,311,594, 3,329,657, 3,332,834, 3,332,901, 3,352,833,3,248,280, 3,442,754, 3,459,697, 3,483,077, 3,609,126, 4,714,736,3,058,873, 2,926,154, 3,855,158, 3,877,510, 4,515,657, 4,537,657,4,501,862, 4,147,586, 4,129,528 5,082,527, 5,239,047, 5,318,669,5,502,091, 5,525,664, 5,614,597, 5,633,300, 5,656,699, 5,674,358,5,904,808, 5,972,691, 6,179,962, 6,355,137, 6,376,578, 6,429,253,7,175,740, and 7,291,695 all of which are herein incorporated byreference.

To impart capacity of the cationic strength resins it is well known inthe art to add water soluble carboxyl containing polymers to the furnishin conjunction with the cationic resin. Suitable carboxyl containingpolymers include carboxymethylcellulose (CMC) as disclosed in U.S. Pat.Nos. 3,058,873, 3,049,469 and 3,998,690. Anionic polyacrylamide (APAM)polymers are an alternative to using carboxyl containing polymers toimprove wet strength development in conjunction with cationic strengthresins as disclosed in U.S. Pat. Nos. 3,049,469 and 6,939,443. If APAMis utilized rather than CMC, then cellulase enzymes can be utilized tobuild strength without concern that the enzymes would react with the CMCto cleave bonds and shorten the degree of polymerization of the moleculerendering it much less effective. The three types of cellulase enzymesthat could be utilized include endo-cellulases, exo-cellulases, andcellobiase cellulases.

To impart dry strength, polymers belonging to any one of the followingthree categories can be mixed in the furnish separately or incombinations thereof: (i) polymers capable of only forming hydrogenbonds to cellulose fibers such as starch or certain polyacrylamides,(ii) polymers capable of additionally forming ionic bonds to cellulosefibers such as higher cationic polyvinylamines or (iii) polymers capableof covalently bonding to the cellulose fibers such as glyoxylatedpolyacrylamide. The polymers can be synthetic or natural. The polymerscan be cationic, anionic, or amphoteric. The polymers can be copolymers,and may have linear or branched structures. In addition to amphotericstarch, suitable dry strength additives may include, but are not limitedto starch and starch derivatives, glyoxalated polyacrylamide, carboxymethyl cellulose, guar gum, locust bean gum, cationic polyacrylamide,polyvinyl alcohol, anionic polyacrylamide, styrene-butadiene copolymers,vinyl acetate polymers, ethylene-vinyl acetate copolymers, vinylchloride polymers, vinylidene chloride polymers, vinylchloride-vinylidene copolymers, acrylo-nitrile copolymers, acrylicemulsions, styrene-butadiene latexes, elastomeric latex emulsions,ethylene-acrylic copolymers or combinations thereof. Exemplary materialsfor use as dry strength additives include those disclosed in U.S. Pat.Nos. 3,556,932, 3,556,933, 4,035,229, 4,129,722, 4,217,425, 5,085,736,5,320,711, 5,674,362, 5,723,022, 6,224,174, 6,245,874, 6,749,721,7,488,403, 7,589,153, 7,828,934, 7,897013, 4,818,341, 4,940,514,4,957,977, 6,616,807, 7,902,312, and 7,922,867 all of which are hereinincorporated by reference in their entirety.

After formation in the forming section 110, the partially dewatered webis transferred to the drying section 112. Within the drying section 112,the tissue may be dried using through air drying processes which involvethe use of a structured fabric. In an exemplary embodiment, the tissueis dried to a humidity of about 7 to 20% using a through air driermanufactured by Valmet Corporation, of Espoo, Finland. In anotherexemplary embodiment, two or more through air drying stages are used inseries. However, it should be emphasized that this is only one ofvarious methods of manufacturing an absorbent structure to be used inmanufacturing the laminate of the present invention.

In an exemplary embodiment, the tissue of the present invention ispatterned during the through air drying process using a TAD fabric. FIG.2 shows a TAD fabric, generally designated by reference number 1000,that may be used in a TAD drying process according to an exemplaryembodiment of the present invention. The TAD fabric 1000 has thefollowing attributes:

Round warp yarn in the machine direction with a diameter in the range of0.35 mm to 0.45 mm or flat rectangular warp yarn with a range of 0.29 mmto 0.39 mm height by 0.35 mm to 0.52 mm width;

Round weft yarn in the cross-machine direction with a diameter in therange of 0.40 mm to 0.60 mm;

A weave pattern with the warp yarn passing over three consecutive weftyarns, then under three subsequent weft yarns, over the subsequent weftyarn, under the subsequent weft yarn, and then repeating the entiresequence over again throughout the fabric (8-shed weave pattern3×3×1×1); and

The mesh (warp filaments per cross direction distance) is 16 filamentsper centimeter or less with a count (weft filaments per machinedirection distance) of 11 filaments per centimeter or less.

The use of this TAD fabric results in production of an absorbentstructure with surface attributes of Valley Volume (Svo) greater than 11microns and Pit density (pockets per sq. cm) greater than 25 and withmultiple and varied pits or pockets. The large Valley Volume coupledwith high pit density provide for enhanced absorbency without the needfor excessive basis weight.

After the through air drying stage, the absorbent structure inaccordance with exemplary embodiments of the present invention may befurther dried in a second phase using a Yankee drying drum. In anexemplary embodiment, a creping adhesive is applied to the drum prior tothe absorbent structure contacting the drum. The absorbent structureadheres to the drum and is removed using a wear resistant coated crepingblade with a creping shelf of 0.5 mm or less. The creping doctor set upangle is preferably 10 to 35 degrees, while the blade bevel ispreferably 55 to 80 degrees. To further illustrate the creping process,FIG. 3 shows a conventional art creping blade application wherein acreping blade 1 is pressed against a steam heated drum 3 in order tocrepe a tissue web 2. The blade may be provided with a wear resistantmaterial 4 at the blade tip. The distance of the creping shelf 15 is thesame as the thickness of the creping blade 14. In comparison, as shownin FIG. 4 , in accordance with exemplary embodiments of the crepingprocess used for the invention, the distance of the creping shelf 15 hasbeen reduced to 0.5 mm or less by beveling the non-contacting face ofthe blade 12. The angle of the bevel b is selected to obtain the desiredcreping shelf distance. Without being bound by theory, it has beendiscovered that distance of the creping shelf can influence theproperties of the absorbent structure including tensile, bulk, andsoftness since the distance of the creping shelf directly influences thecontact time between the blade and web and thus the forces imparted tothe web by the blade. In an exemplary embodiment, a 25 degree blade setup angle (c), which is measured from a normal line at the contact pointbetween the blade tip and the drum to the face of the creping blade 5, awear resistant coated tip blade with an 80 degree blade bevel (d), and a0.5 mm creping shelf distance 15 is utilized.

The wear resistant material is suitably a ceramic material, a cermetmaterial, or a carbide material. For example, the wear resistantmaterial may be selected from metal oxides, ceramic materials,silicates, carbides, borides, nitrides, and mixtures thereof. Particularexamples of suitable wear resistant materials are alumina, chromia,zirconia, tungsten carbide, chromium carbide, zirconium carbide,tantalum carbide, titanium carbide, and mixtures thereof. Thewear-resistant material may be applied by thermal spraying, physicalvapor deposition, or chemical vapor deposition.

The tissue may then be calendered in a subsequent stage within thecalendar section 114. According to an exemplary embodiment, calendaringmay be accomplished using a number of calendar rolls (not shown) thatdeliver a calendering pressure in the range of 0-100 pounds per linearinch (PLI). In general, increased calendering pressure is associatedwith reduced caliper and a smoother tissue surface.

According to an exemplary embodiment of the invention, a ceramic coatedcreping blade is used to remove the absorbent structure from the Yankeedrying drum. Ceramic coated creping blades result in reduced adhesivebuild up and aid in achieving higher run speeds. Without being bound bytheory, it is believed that the ceramic coating of the creping bladesprovides a less adhesive surface than metal creping blades and is moreresistant to edge wear that can lead to localized spots of adhesiveaccumulation. The ceramic creping blades allow for a greater amount ofcreping adhesive to be used which in turn provides improved sheetintegrity and faster run speeds.

In addition to the use of wet end additives, the absorbent structure inaccordance with exemplary embodiments of the present invention may alsobe treated with topical or surface deposited additives. Examples ofsurface deposited additives include softeners for increasing fibersoftness and skin lotions. Examples of topical softeners include but arenot limited to quaternary ammonium compounds, including, but not limitedto, the dialkyldimethylammonium salts (e.g. ditallowdimethylammoniumchloride, ditallowdimethylammonium methyl sulfate, di(hydrogenatedtallow)dimethyl ammonium chloride, etc.). Another class of chemicalsoftening agents include the organo-reactive polydimethyl siloxaneingredients, including amino functional polydimethyl siloxane, zincstearate, aluminum stearate, sodium stearate, calcium stearate,magnesium stearate, spermaceti, and steryl oil.

To enhance the strength and absorbency of the absorbent structure,multiple plies are laminated together using, for example, a heatedadhesive, as described below with respect to FIG. 5 . The adhesivemixture is preferably water soluble and includes a mixture of one ormore adhesives, one or more water soluble cationic resins and water. Theone or more adhesives are present in an amount of 1% to 10% by weight ofthe mixture and may be polyvinyl alcohol, polyvinyl acetate, starchbased resins and/or mixtures thereof. A water soluble cationic resin maybe present in an amount of up to 10% by weight of the mixture and mayinclude polyamide-epichlorohydrin resins, glyoxalated polyacrylamideresins, polyethyleneimine resins, polyethylenimine resins, and/ormixtures thereof. The remainder of the mixture is composed of water.

FIG. 5 shows an apparatus for manufacturing a laminate of two plies of astructured paper towel or tissue that are joined to each other, with theYankee side surface of each ply facing the exterior of the laminatedstructure, in accordance with an exemplary embodiment of the presentinvention. The process illustrated in FIG. 5 is referred to as dynamicembossment knock out (DEKO) embossing. As shown, two webs 200, 201 ofsingle ply towel which may be manufactured, for example, according tothe methods described herein are plied together with only one web beingembossed. A first web 200 is fed through a nip 202A formed by rubbercovered pressure roll 203 and embossing roll 204 (also known as apatterned roll). The embossing roll 204 which rotates in the illustrateddirection, impresses an embossment pattern onto the web 200 as it passesthrough the nip between emboss roll 204 and pressure roll 203. A secondweb 201 is fed across two idler rolls 205 and joins with web 200 at thenip between the embossing roll 204 and marrying roll 214. The idlersrolls can be driven. Alternatively, the emboss section may not haveidler rolls, in which case the second web would travel directly to thenip between the embossing roll 204 and marrying roll 214.

After being embossed, the top ply may have a plurality of embossmentsprotruding outwardly from the plane of the ply towards the adjacent ply.The emboss roll 204 has embossing tips or embossing knobs that extendradially outward from the rolls to make the embossments. In theillustrated embodiment, embossing is performed by the crests of theembossing knobs applying pressure onto the rubber pressure roll andcompressing and deflecting web 200 into the pressure roll 203 andthereby imparting the imprint of the embossments into the paper web.

An adhesive applicator roll 212 is positioned upstream of emboss roll204 and is aligned in an axially parallel arrangement with the embossroll. The heated adhesive is fed from an adhesive tank 207 via a conduit210 to applicator roll 212. The applicator roll 212 transfers heatedadhesive to an interior side of embossed ply 200 to adhere the at leasttwo plies 200, 201 together, wherein the interior side is the side ofply 200 that comes into a face-to-face relationship with ply 201 forlamination. The adhesive is applied to the ply at the crests of theembossing knobs on embossing roll 204. In a preferred exemplaryembodiment, adhesive is applied only to the tips of the embossmentsformed in the ply 200.

Notably, in exemplary embodiments of the present invention, the adhesiveis heated and maintained at a desired temperature utilizing, inembodiments, the adhesive tank 207, which is an insulated stainlesssteel tank that may have heating elements 208 that are substantiallyuniformly distributed throughout the interior heating surface. In thismanner, a large amount of surface area may be heated relativelyuniformly. Generally, an adjustable thermostat may be used to controlthe temperature of the adhesive tank 207. It has been found advantageousto maintain the temperature of the adhesive at between approximately 32degrees C. (90 degrees F.) to 66 degrees C. (150 degrees F.), andpreferably to around 49 degrees C. (120 degrees F.). In addition, inembodiments, the tank has an agitator 209 to ensure proper mixing andheat transfer.

After the application of the embossments and the adhesive, a marryingroll 214 is used to apply pressure for lamination. The marrying roll 214forms a nip with the embossing roll 204. The marrying roll 214 isgenerally needed to apply pressure to the two webs to allow the adhesiveon the crests of the embossments on web 200 to contact and adhere to andlaminate to web 201.

The specific pattern that is embossed on the absorbent products issignificant for achieving the enhanced scrubbing resistance of thepresent invention. In particular, it has been found that the embossedarea on the top ply should cover between approximately 5 to 15% of thesurface area. Moreover, the size of each embossment should be betweenapproximately 0.04 to 0.08 square centimeters. The depth of theembossment should be within the range of between approximately 0.127 and0.43 centimeters (0.050 and 0.170 inches) in depth.

The emboss pattern used is also important to provide adequate area forbonding the laminate while limiting absorbency loss, as the laminatedareas will absorb less than the non-laminated areas. In a preferredexemplary embodiment, the embossed area on any ply should be in therange of 5% to 15%. The size of each embossment is preferably in therange of 0.04 to 0.08 square centimeters. The depth of each embossmentis preferably in the range of 0.05 and 0.170 inches.

The combination of the structuring fabric and lamination method providesa disposable towel product with high levels of absorbency at low levelsof basis weight with good strength and performance.

Ball Burst Testing

The Ball Burst of a 2-ply tissue web was determined using a TissueSoftness Analyzer (TSA), available from Emtec Electronic GmbH ofLeipzig, Germany using a ball burst head and holder. A punch was used tocut out five 100 cm² round samples from the web. One of the samples wasloaded into the TSA, with the embossed surface facing down, over theholder and held into place using the ring. The ball burst algorithm wasselected from the list of available softness testing algorithmsdisplayed by the TSA. The ball burst head was then pushed by the TSAthrough the sample until the web ruptured and calculated the grams forcerequired for the rupture to occur. The test process was repeated for theremaining samples and the results for all the samples were averaged.

Stretch & MD, CD, and Wet CD Tensile Strength Testing

An Instron 3343 tensile tester, manufactured by Instron of Norwood,Mass., with a 100N load cell and 25.4 mm rubber coated jaw faces, wasused for tensile strength measurement. Prior to measurement, the Instron3343 tensile tester was calibrated using Operator's Guide M10-16279-EMRevision D. After calibration, 8 strips of 2-ply product, each 2.54 cmby 10.16 cm (one inch by four inches), were provided as samples for eachtest. When testing MD (Material Direction) tensile strength, the stripswere cut in the MD direction. When testing CD (Cross Direction) tensilestrength, the strips were cut in the CD direction. One of the samplestrips was placed in between the upper jaw faces and clamp, and thenbetween the lower jaw faces and clamped with a gap of 5.08 cm (2 inches)between the clamps. A test was run on the sample strip to obtain tensilestrength and stretch. The test procedure was repeated until all thesamples were tested. The values obtained for the eight sample stripswere averaged to determine the tensile strength of the tissue. Whentesting CD wet tensile, the strips were placed in an oven at 105 degreesCelsius for 5 minutes and saturated with 75 microliters of deionizedwater at the center of the strip across the entire cross directionimmediately prior to pulling the sample.

Basis Weight

Using a dye and press, six 76.2 mm by 76.2 mm square samples were cutfrom a 2-ply product being careful to avoid any web perforations. Thesamples were placed in an oven at 105 deg C. for 5 minutes before beingweighed on an analytical balance to the fourth decimal point. The weightof the sample in grams was divided by (0.0762 m)² to determine the basisweight in grams/m².

Caliper Testing

A Thwing-Albert ProGage 100 Thickness Tester, manufactured by ThwingAlbert of West Berlin, N.J. was used for the caliper test. The ThicknessTester was used with a 2 inch diameter pressure foot with a presetloading of 0.93 grams/square inch. Eight 100 mm×100 mm square sampleswere cut from a 2-ply product. The samples were then tested individuallyand the results were averaged to obtain a caliper result for the basesheet.

Softness Testing

Softness of a 2-ply tissue web was determined using a Tissue SoftnessAnalyzer (TSA), available from Emtec Electronic GmbH of Leipzig,Germany. The TSA comprises a rotor with vertical blades which rotate onthe test piece to apply a defined contact pressure. Contact between thevertical blades and the test piece creates vibrations which are sensedby a vibration sensor. The sensor then transmits a signal to a PC forprocessing and display. The frequency analysis in the range ofapproximately 200 to 1000 Hz represents the surface smoothness ortexture of the test piece and is referred to as the TS750 value. Afurther peak in the frequency range between 6 and 7 kHz represents thebulk softness of the test piece and is referred to as the TS7 value.Both TS7 and TS750 values are expressed as dB V² rms. The stiffness ofthe sample is also calculated as the device measures deformation of thesample under a defined load. The stiffness value (D) is expressed asmm/N. The device also calculates a Hand Feel (HF) number with the valuecorresponding to a softness as perceived when someone touches a tissuesample by hand (the higher the HF number, the higher the softness). TheHF number is a combination of the TS750, TS7, and stiffness of thesample measured by the TSA and calculated using an algorithm which alsorequires the caliper and basis weight of the sample. Differentalgorithms can be selected for different facial, toilet, and towel paperproducts. Before testing, a calibration check should be performed using“TSA Leaflet Collection No. 9” (dated 2016 May 10) available from Emtec.If the calibration check demonstrates a calibration is necessary, “TSALeaflet Collection No. 10” is followed for the calibration procedureavailable from Emtec dated 2015 Sep. 9.

A punch was used to cut out five 100 cm² round samples from the web. Oneof the samples was loaded into the TSA, clamped into place (outwardfacing or embossed ply facing upward), and the TPII algorithm wasselected from the list of available softness testing algorithmsdisplayed by the TSA. After inputting parameters for the sample(including caliper and basis weight), the TSA measurement program wasrun. The test process was repeated for the remaining samples and theresults for all the samples were averaged and the average HF numberrecorded.

Valley Volume (Svo) and Pit Density

Valley Volume is a parameter that measures valley volume per unit areain a sample's 3D data set through the use of its material ratio curve,shown in FIG. 6 . The most horizontal line in a 40% wide region of thematerial ratio curve is recognized and a straight line is drawn thatextends the whole length of the curve. The region shown in gray belowthe horizontal line is considered the valley area, but when using a 3Ddata set, it is the valley volume.

Svo can be further understood by referencing ISO 25178-2, the contentsof which are incorporated herein by reference in their entirety.

Pit Density—measures the number of pockets in the sample that do nottravel the entire x or y axis in the given field of view. These pockets,or pits, are totally contained or framed as shown in the far rightwindow of FIG. 7 . The objective of this test method is to eliminateconfusion when trying to count openings in the paper. The openings areirregular shaped and have different depths. The goal of the Pit Densitytest is to count the number of openings regardless of shape.

Images used to calculate the Valley Volume (Svo) and Pit Density wereacquired using a Keyence Model VR-3200 G2 3D Macroscope equipped withmotorized XY stage, VR-3000K controller, VR-H2VE version 2.2.0.89 Viewersoftware, and VR-H2AE Analyzer software. After following calibrationprocedures, as outlined by the Keyence equipment manual from 2016, theinstrument was configured for 25× magnification. The following wasselected on the viewer software: “Expert mode” for viewer capturemethod, and “normal” capture image type for Camera settings. ForMeasurement settings: “Glare removal” mode was selected with “bothsides” measurement direction, Adjust brightness for measurement set to“Auto,” and Display missing and saturated data turned “ON.” This resultsin a “3D surface data set” which is approximately 12.1 mm (X direction)by 9.1 mm (Y direction) with a pixel size of approximately 7.9 microns.

On paper towels, the top surface of the top ply is the surface ofinterest, avoiding any and all emboss points if possible. Embossmentsare not representative of the majority of the surface and should beavoided during the “3D surface data set” acquisition. A representativepaper towel sheet was torn from the center of a roll and held in placeusing weights. When tearing the sheet from the roll, care was taken tonot alter the topographic features of the sample. The machine direction(MD) of the sample was placed in the Y axis (front to back on the stageas seen from operator perspective in front of the system) while thecross direction (CD) was placed in the X axis (left to right on thestage as seen from operator perspective in front of the system). Carewas taken to ensure no creases or folds were present in the sample andthe sample was not under any MD or CD directional stress. The image wasautofocused prior to capturing the “3D surface data set”. Ten of these“3D surface data sets” were collected for each sample.

“3D surface data sets” were exported from the analyzer software withimage type “Height” and the “No Skip” option selected. These “3D surfacedata sets” were analyzed with OmniSurf3D (v1.01.052) software, availablefrom Digital Metrology Solutions, Inc. of Columbus, Ind., USA forparameter calculations.

The OmniSurf3D settings were set as follows:

Preprocessing: Alignment—Auto-trim to Valid, Edge Discarding —Use alldata,

Outlier Removal—None, Missing Data Filling—Linear Fill, DataInversion—None, Transform, Rotate—0,

Geometry: Reference Geometry—Polynomial, X-order=4, Y-order=4,

Filtering: Short Wavelength Limitation—Gaussian/0.80000 mm/Sync X&Y,

Long Wavelength Limitation-Gaussian/8.00000 mm/Sync X&Y, Post-FilterEdge Discarding—None

The Pre-processing settings are shown in FIG. 8 . The Geometry Settingsare shown in FIG. 9 . The Filtering settings are shown in FIG. 10 .

The settings described above were chosen to remove underlying curvaturesin the samples. The desired exported file from the Keyence software wasopened in the Omnisurf 3D software. In the “analysis” menu, “parameters”was selected, and Svo was chosen. The user clicked “OK” and the Svovalue was recorded. For Pit Density, the “Pit/Porosity Analysis” toolwas selected in the “Tools” menu. “Height Above Meanline” was chosen andthe height was set to 0. The user clicked “Apply” and the Pit Densitywas recorded.

Absorbency Testing

An M/K GATS (Gravimetric Absorption Testing System), manufactured by M/KSystems, Inc., of Peabody, Mass., USA was used to test absorbency usingMK Systems GATS Manual from Mar. 30, 2016. Absorbency is reported asgrams of water absorbed per gram of absorbent product. The followingsteps were followed during the absorbency testing procedure:

Turn on the computer and the GATS machine. The main power switch for theGATS is located on the left side of the front of the machine and a redlight will be illuminated when power is on. Ensure the balance is on. Abalance should not be used to measure masses for a least 15 minutes fromthe time it is turned on. Open the computer program by clicking on the“MK GATS” icon and click “Connect” once the program has loaded. If thereare connectivity issues, make sure that the ports for the GATS andbalance are correct, the GATS being attached to “COM7” and the balancebeing attached to “COMB”. These can be seen in Full Operational Mode.The upper reservoir of the TAS needs to be filled with Deionized water.The Velmex slide level for the wetting stage needs to be set at 4.5 cm.If the slide is not at the proper level, movement of it can only beaccomplished in Full Operational Mode. Click the “Direct Mode” check boxlocated in the top left of the screen to take the system out of DirectMode and put into Full Operational Mode. The level of the wetting stageis adjusted in the third window down on the left side of the softwarescreen. To move the slide up or down 1 cm at a time, the button for “1cm up” and “1 cm down” can be used. If a millimeter adjustment isneeded, press and hold the shift key while toggling the “1 cm up” or “1cm down” icons. This will move the wetting stage 1 mm at a time. Clickthe “Test Options” Icon and ensure the following set-points areinputted: “Dip Start” selected with 10.0 mm inputted under “Absorption”,“Total Weight change (g)” selected with 0.1 inputted under “Start At”,Rate (g) selected with 0.05 inputted per (sec) 5 under “End At” on theleft hand side of the screen, “Number of Raises” 1 inputted and regularraises (mm) 10 inputted under “Desorption”, Rate (g) selected with −0.03inputted per 5 sec under “End At” on the right hand side of the screen.These selections are also shown in FIG. 8 . The water level in theprimary reservoir needs to be filled to the operational level before anyseries of testing. This involves the reservoir and water contained in itto be set to 580 grams total mass. Click on the “Setup” icon in the boxlocated in the top left of the screen. The reservoir will need to belifted to allow the balance to tare or zero itself. The feed and drawtubes for the system are located on the side and extend into thereservoir. Prior to lifting the reservoir, ensure that the top hatch onthe balance is open to keep from damaging the top of the balance or theelevated platform that the sample is weighed on. Open the side door ofthe balance to lift the reservoir. Once the balance reading is stable amessage will appear to place the reservoir again. Ensure that thereservoir doesn't make contact with the walls of the balance. Close theside door of the balance. The reservoir will need to be filled to obtainthe mass of 580 g. Once the reservoir is full, the system will be readyfor testing. The system is now ready to test. Obtain a minimum number offour 113 mm diameter circular samples. Three will be tested with oneextra available. Enter the pertinent sample information in the “EnterMaterial ID.” section of the software. The software will automaticallydate and number the samples as completed with any used entered data inthe center of the file name. Click the “Run Test” icon. The balance willautomatically zero itself. Place the pre-cut sample on the elevatedplatform, making sure the sample isn't in contact with the balance lid.Once the balance load is stabilized, click “Weigh”. Move the sample tothe wetting stage, centered with the emboss facing down. Ensure thesample doesn't touch the sides and place the cover on the sample. Click“Wet the Sample”. The wetting stage will drop the preset distance toinitiate absorption. The absorption will end when the rate of absorptionis less than 0.05 grams/5 seconds. When absorption stops, the wettingstage will rise to conduct desorption. Data for desorption isn'trecorded for tested sample. Remove the saturated sample and dry thewetting stage prior to the next test. Once the test is complete, thesystem will automatically refill the reservoir. Record the datagenerated for this sample. The data that is traced for each sample isthe dry weight of the sample (in grams), the normalized total absorptionof the sample reflected in grams of water/gram of product, and thenormalized absorption rate in grams of water per second. Repeatprocedure for the three samples and report the average total absorbency.

The towel of the present invention exhibits a unique Valley Volume Svoof greater than 11 microns and Pit density (pockets per sq cm.) ofgreater than 25 with multiple and varied pits/pockets.

The following example illustrates advantages of the present invention.

Example 1

Paper towel made on a wet-laid asset with a three layer headbox wasproduced using the through air drying method. A TAD fabric weave patternwas used with the warp yarn passing over three consecutive weft yarns,then under three subsequent weft yarns, over the subsequent weft yarn,under the subsequent weft yarn, and then repeating the entire sequenceover again throughout the fabric was utilized. The fabric had a 16filaments/cm Mesh and 11 filaments/cm Count, a 0.40 mm diameter roundwarp monofilament, a 0.55 mm diameter round weft monofilament, a 1.17 mmcaliper, with a 620 cfm and a knuckle surface that was sanded to impart15% contact area with the Yankee dryer. The flow to each layer of theheadbox was about 33% of the total sheet. The three layers of thefinished tissue from top to bottom were labeled as air, core and dry.The air layer is the outer layer that is placed on the TAD fabric, thedry layer is the outer layer that is closest to the surface of theYankee dryer and the core is the center section of the tissue. Thetissue was produced with 50% NBSK and 50% eucalyptus in the Yankee layerwith 80% NB SK, 20% eucalyptus in the core and air layer. Polyaminepolyamide-epichlorohydrin resin at 8.0 kg/ton (dry basis) and 3.5 kg/ton(dry basis) of anionic polyacrylamide were added to each of the threelayers to generate permanent wet strength. The NBSK was refinedseparately before blending into the layers using 80 kwh/ton on oneconical refiner. The Yankee and TAD section speed was 1350 m/min running12% slower than the forming section. The Reel section was additionallyrunning 1% slower than the Yankee. The towel was then plied togetherusing the method described herein using a steel emboss roll with thepattern shown in FIG. 13 and 7% polyvinyl alcohol based adhesive heatedto 120 deg F. A rolled 2-ply product was produced with 146 sheets and aroll diameter of 150 mm, with each sheet having a length of 6.0 inchesand a width of 11 inches. The 2-ply tissue product had the followingproduct attributes: Basis Weight 39.8 g/m², Caliper 0.843 mm, MD tensileof 410 N/m, CD tensile of 388 N/m, a ball burst of 898 grams force, anMD stretch of 17.9%, a CD stretch of 8.8%, a CD wet tensile of 113 N/m,an absorbency of 18.3 g/g, and a TSA softness of 46.6. The Svo value was14.3 microns, with a Pit Density of 32.3 pockets per sq cm. FIG. 11shows an image of the surface of the disposable paper towel produced inthis Example magnified at 20 times.

Comparative Example

Paper towel made on a wet-laid asset with a three layer headbox wasproduced using the through air dried method. A TAD fabric design namedProlux 593 supplied by Albany (216 Airport Drive Rochester, N.H. 03867USA Tel: +1.603.330.5850) was utilized. The fabric had a 45 yarns/inchMesh and 27 yarns/inch Count, a 0.35 mm warp monofilament, a 0.55 mmweft monofilament, a 1.89 mm caliper, with a 670 cfm and a knucklesurface that was sanded to impart 15% contact area with the Yankeedryer. The flow to each layer of the headbox was about 33% of the totalsheet. The three layers of the finished tissue from top to bottom werelabeled as air, core and dry. The air layer is the outer layer that isplaced on the TAD fabric, the dry layer is the outer layer that isclosest to the surface of the Yankee dryer and the core is the centersection of the tissue. The tissue was produced with 50% NBSK and 50%eucalyptus in the Yankee layer with 80% NB SK, 20% eucalyptus in thecore and air layer. Polyamine polyamide-epichlorohydrin resin at 12.0kg/ton (dry basis) and 4.0 kg/ton (dry basis) of carboxymethylcellulosewere added to each of the three layers to generate permanent wetstrength. Additionally, 1.5 kg/ton of polyvinyl amine was added to eachlayer to aid in fiber retention with 2.0 kg of amphoteric starch foradditional strength generation. The NBSK was refined separately beforeblending into the layers using 100 kwh/ton on one conical refiner. TheYankee and TAD section speed was 1200 m/min running 17% slower than theforming section. The Reel section was additionally running 1% fasterthan the Yankee. The towel was then plied together using the methoddescribed herein using a steel emboss roll with the pattern shown inFIG. 13 and 7% polyvinyl alcohol based adhesive heated to 120 deg F. Arolled 2-ply product was produced with 146 sheets and a roll diameter of147 mm, with each sheet having a length of 6.0 inches and a width of 11inches. The 2-ply tissue product had the following product attributes:Basis Weight 39.09 g/m², Caliper 0.880 mm, MD tensile of 429 N/m, CDtensile of 491 N/m, a ball burst of 1098 grams force, an MD stretch of21.4%, a CD stretch of 13.3%, a CD wet tensile of 146 N/m, an absorbencyof 15.9 g/g, and a TSA softness of 44.4. Svo value was 6.9 microns, witha Pit Density of 43 pockets per sq cm.

FIG. 12 shows the surface parameters and physical properties of theComparative Example and various commercially available disposable towelproducts compared to Example 1.

Now that embodiments of the present invention have been shown anddescribed in detail, various modifications and improvements thereon willbecome readily apparent to those skilled in the art. Accordingly, thespirit and scope of the present invention is to be construed broadly andnot limited by the foregoing specification.

The invention claimed is:
 1. Disposable roll product comprising: athrough-air-dried towel with a laminate of at least two multi-layerplies, wherein the product has a measured Valley Volume parameterbetween 11 microns and 21 microns and a Pit Density between 25 pocketsper sq. cm and 40 pockets per sq. cm, wherein a GATS total absorption ofthe product is between 16.0 grams water/grams of towel and 19.0 gramswater/grams of towel.
 2. The disposable roll product of claim 1, whereinthe product is produced using a wet laid structured tissue process. 3.The disposable roll product of claim 1, wherein at least one of the atleast two multi-layer plies comprises cellulosic-based fibers.
 4. Thedisposable roll product of claim 3, wherein the cellulosic-based fibersare selected from the group consisting of wood pulp, cannabis, cotton,regenerated or spun cellulose, jute, flax, ramie, bagasse, kenaf fibersand combinations thereof.
 5. The disposable roll product of claim 1,wherein at least one of the at least two plies is embossed and two ormore of at least two plies are adhered together.
 6. The disposable rollproduct of claim 5, wherein the two or more plies are adhered togetherwith a water-soluble adhesive mixture comprised of polyvinyl alcohol,polyvinyl acetate, starch-based resins or mixtures thereof.
 7. Thedisposable roll product of claim 6, wherein the water-soluble adhesivemixture is applied to at least one ply of the two or more plies at atemperature within a range of 32 degrees C. to 66 degrees C.
 8. Thedisposable roll product of claim 6, wherein the water-soluble adhesivemixture further comprises a water-soluble cationic resin selected fromthe group consisting of polyamide-epichlorohydrin resins, glyoxalatedpolyacrylamide resins, polyethyleneimine resins, polyethylenimineresins, and mixtures thereof.
 9. The disposable roll product of claim 1,wherein at least one ply of the at least two multi-layer plies comprisesan embossed area, and the embossed area occupies between 5 to 20% of atotal surface area of a surface of the at least one ply.
 10. Thedisposable roll product of claim 1, wherein each of the at least twoplies comprises an embossed area having a surface, wherein a depth ofembossment of the surface is between 0.28 centimeters and 0.43centimeters.
 11. The disposable roll product of claim 1, wherein each ofthe at least two plies comprise an embossed area having a surface,wherein each embossment of the surface is between 0.04 squarecentimeters and 0.08 square centimeters in size.
 12. Disposable rollproduct comprising: a through-air-dried towel with a laminate of atleast two multi-layer plies, wherein the product has a measured ValleyVolume parameter between 11 microns and 21 microns and a Pit Densitybetween 25 pockets per sq. cm and 40 pockets per sq. cm, wherein thedisposable towel product has a basis weight of between 35 grams persquare meter and 48 grams per square meter.
 13. The disposable rollproduct of claim 12, wherein the product is produced using a wet laidstructured tissue process.
 14. The disposable roll product of claim 12,wherein at least one of the at least two multi-layer plies comprisescellulosic-based fibers.
 15. The disposable roll product of claim 14,wherein the cellulosic-based fibers are selected from the groupconsisting of wood pulp, cannabis, cotton, regenerated or spuncellulose, jute, flax, ramie, bagasse, kenaf fibers and combinationsthereof.
 16. The disposable roll product of claim 12, wherein at leastone of the at least two plies is embossed and two or more of at leasttwo plies are adhered together.
 17. The disposable roll product of claim16, wherein the two or more plies are adhered together with awater-soluble adhesive mixture comprised of polyvinyl alcohol, polyvinylacetate, starch-based resins or mixtures thereof.
 18. The disposableroll product of claim 17, wherein the water-soluble adhesive mixture isapplied to at least one ply of the two or more plies at a temperaturewithin a range of 32 degrees C. to 66 degrees C.
 19. The disposable rollproduct of claim 17, wherein the water-soluble adhesive mixture furthercomprises a water soluble cationic resin selected from the groupconsisting of polyamide-epichlorohydrin resins, glyoxalatedpolyacrylamide resins, polyethyleneimine resins, polyethylenimineresins, and mixtures thereof.
 20. The disposable roll product of claim12, wherein at least one ply of the at least two multi-layer pliescomprises an embossed area, and the embossed area occupies between 5 to20% of a total surface area of a surface of the at least one ply. 21.The disposable roll product of claim 12, wherein each of the at leasttwo plies comprises an embossed area having a surface, wherein a depthof embossment of the surface is between 0.28 centimeters and 0.43centimeters.
 22. The disposable roll product of claim 12, wherein eachof the at least two plies comprise an embossed area having a surface,wherein each embossment of the surface is between 0.04 squarecentimeters and 0.08 square centimeters in size.
 23. Disposable rollproduct comprising: a through-air-dried towel with a laminate of atleast two multi-layer plies, wherein the product has a measured ValleyVolume parameter between 11 microns and 21 microns and a Pit Densitybetween 25 pockets per sq. cm and 40 pockets per sq. cm, wherein a GATStotal absorption of the product is between 16.0 grams water/grams oftowel and 19.0 grams water/grams of towel, and the disposable rollproduct has a basis weight of between 35 grams per square meter and 48grams per square meter.
 24. The disposable roll product of claim 23,wherein the product is produced using a wet laid structured tissueprocess.
 25. The disposable roll product of claim 23, wherein at leastone of the at least two multi-layer plies comprises cellulosic-basedfibers.
 26. The disposable roll product of claim 25, wherein thecellulosic-based fibers are selected from the group consisting of woodpulp, cannabis, cotton, regenerated or spun cellulose, jute, flax,ramie, bagasse, kenaf fibers and combinations thereof.
 27. Thedisposable roll product of claim 23, wherein at least one of the atleast two plies is embossed and two or more of at least two plies areadhered together.
 28. The disposable roll product of claim 27, whereinthe two or more plies are adhered together with a water-soluble adhesivemixture comprised of polyvinyl alcohol, polyvinyl acetate, starch-basedresins or mixtures thereof.
 29. The disposable roll product of claim 28,wherein the water-soluble adhesive mixture is applied to at least oneply of the two or more plies at a temperature within a range of 32degrees C. to 66 degrees C.
 30. The disposable roll product of claim 28,wherein the water-soluble adhesive mixture further comprises awater-soluble cationic resin selected from the group consisting ofpolyamide-epichlorohydrin resins, glyoxalated polyacrylamide resins,polyethyleneimine resins, polyethylenimine resins, and mixtures thereof.31. The disposable roll product of claim 23, wherein at least one ply ofthe at least two multi-layer plies comprises an embossed area, and theembossed area occupies between 5 to 20% of a total surface area of asurface of the at least one ply.
 32. The disposable roll product ofclaim 23, wherein each of the at least two plies comprises an embossedarea having a surface, wherein a depth of embossment of the surface isbetween 0.28 centimeters and 0.43 centimeters.
 33. The disposable rollproduct of claim 23, wherein each of the at least two plies comprise anembossed area having a surface, wherein each embossment of the surfaceis between 0.04 square centimeters and 0.08 square centimeters in size.34. A disposable towel product comprising: a laminate of at least twomulti-layer plies, wherein the product has a measured Valley Volumeparameter of greater than 11 microns and a Pit Density of greater than25 pockets per sq. cm, wherein a GATS total absorption of the product isbetween 16.0 grams water/grams of towel and 19.0 grams water/grams oftowel.
 35. The disposable towel product of claim 34, wherein the productis produced using a wet laid structured tissue process.
 36. Thedisposable towel product of claim 34, wherein at least one of the atleast two multi-layer plies comprises cellulosic-based fibers.
 37. Thedisposable towel product of claim 36, wherein the cellulosic-basedfibers are selected from the group consisting of wood pulp, cannabis,cotton, regenerated or spun cellulose, jute, flax, ramie, bagasse, kenaffibers and combinations thereof.
 38. The disposable towel product ofclaim 34, wherein at least one of the at least two plies is embossed andtwo or more of at least two plies are adhered together.
 39. Thedisposable towel product of claim 38, wherein the two or more plies areadhered together with a water-soluble adhesive mixture comprised ofpolyvinyl alcohol, polyvinyl acetate, starch-based resins or mixturesthereof.
 40. The disposable towel product of claim 39, wherein thewater-soluble adhesive mixture is applied to at least one ply of the twoor more plies at a temperature within a range of 32 degrees C. to 66degrees C.
 41. The disposable towel product of claim 39, wherein thewater-soluble adhesive mixture further comprises a water-solublecationic resin selected from the group consisting ofpolyamide-epichlorohydrin resins, glyoxalated polyacrylamide resins,polyethyleneimine resins, polyethylenimine resins, and mixtures thereof.42. The disposable towel product of claim 34, wherein at least one plyof the at least two multi-layer plies comprises an embossed area, andthe embossed area occupies between 5 to 20% of a total surface area of asurface of the at least one ply.
 43. The disposable towel product ofclaim 34, wherein each of the at least two plies comprise an embossedarea having a surface, wherein a depth of embossment of the surface isbetween 0.28 centimeters and 0.43 centimeters.
 44. The disposable towelproduct of claim 34, wherein each of the at least two plies comprise anembossed area having a surface, wherein each embossment of the surfaceis between 0.04 square centimeters and 0.08 square centimeters in size.45. A disposable towel product comprising: a laminate of at least twomulti-layer plies, wherein the product has a measured Valley Volumeparameter of greater than 11 microns and a Pit Density of greater than25 pockets per sq. cm, wherein the disposable towel product has a basisweight of between 35 grams per square meter and 45 grams per squaremeter.
 46. The disposable towel product of claim 45, wherein the productis produced using a wet laid structured tissue process.
 47. Thedisposable towel product of claim 45, wherein at least one of the atleast two multi-layer plies comprises cellulosic-based fibers.
 48. Thedisposable towel product of claim 47, wherein the cellulosic-basedfibers are selected from the group consisting of wood pulp, cannabis,cotton, regenerated or spun cellulose, jute, flax, ramie, bagasse, kenaffibers and combinations thereof.
 49. The disposable towel product ofclaim 45, wherein at least one of the at least two plies is embossed andtwo or more of at least two plies are adhered together.
 50. Thedisposable towel product of claim 49, wherein the two or more plies areadhered together with a water-soluble adhesive mixture comprised ofpolyvinyl alcohol, polyvinyl acetate, starch-based resins or mixturesthereof.
 51. The disposable towel product of claim 50, wherein thewater-soluble adhesive mixture is applied to at least one ply of the twoor more plies at a temperature within a range of 32 degrees C. to 66degrees C.
 52. The disposable towel product of claim 50, wherein thewater-soluble adhesive mixture further comprises a water-solublecationic resin selected from the group consisting ofpolyamide-epichlorohydrin resins, glyoxalated polyacrylamide resins,polyethyleneimine resins, polyethylenimine resins, and mixtures thereof.53. The disposable towel product of claim 45, wherein at least one plyof the at least two multi-layer plies comprises an embossed area, andthe embossed area occupies between 5 to 20% of a total surface area of asurface of the at least one ply.
 54. The disposable towel product ofclaim 45, wherein each of the at least two plies comprises an embossedarea having a surface, wherein a depth of embossment of the surface isbetween 0.28 centimeters and 0.43 centimeters.
 55. The disposable towelproduct of claim 45, wherein each of the at least two plies comprise anembossed area having a surface, wherein each embossment of the surfaceis between 0.04 square centimeters and 0.08 square centimeters in size.56. A disposable towel product comprising: a laminate of at least twomulti-layer plies, wherein the product has a measured Valley Volumeparameter of between 11 microns and 21 microns and a Pit Density ofbetween 25 pockets per sq. cm and 40 pockets per sq. cm, wherein a GATStotal absorption of the product is between 16.0 grams water/grams oftowel and 19.0 grams water/grams of towel, and the disposable towelproduct has a basis weight of between 35 grams per square meter and 45grams per square meter.
 57. The disposable towel product of claim 56,wherein the product is produced using a wet laid structured tissueprocess.
 58. The disposable towel product of claim 56, wherein at leastone of the at least two multi-layer plies comprises cellulosic-basedfibers.
 59. The disposable towel product of claim 58, wherein thecellulosic-based fibers are selected from the group consisting of woodpulp, cannabis, cotton, regenerated or spun cellulose, jute, flax,ramie, bagasse, kenaf fibers and combinations thereof.
 60. Thedisposable towel product of claim 56, wherein at least one of the atleast two plies is embossed and two or more of at least two plies areadhered together.
 61. The disposable towel product of claim 60, whereinthe two or more plies are adhered together with a water-soluble adhesivemixture comprised of polyvinyl alcohol, polyvinyl acetate, starch-basedresins or mixtures thereof.
 62. The disposable towel product of claim61, wherein the water-soluble adhesive mixture is applied to at leastone ply of the two or more plies at a temperature within a range of 32degrees C. to 66 degrees C.
 63. The disposable towel product of claim61, wherein the water-soluble adhesive mixture further comprises awater-soluble cationic resin selected from the group consisting ofpolyamide-epichlorohydrin resins, glyoxalated polyacrylamide resins,polyethyleneimine resins, polyethylenimine resins, and mixtures thereof.64. The disposable towel product of claim 56, wherein at least one plyof the at least two multi-layer plies comprises an embossed area, andthe embossed area occupies between 5 to 20% of a total surface area of asurface of the at least one ply.
 65. The disposable towel product ofclaim 56, wherein each of the at least two plies comprises an embossedarea having a surface, wherein a depth of embossment of the surface isbetween 0.28 centimeters and 0.43 centimeters.
 66. The disposable towelproduct of claim 56, wherein each of the at least two plies comprise anembossed area having a surface, wherein each embossment of the surfaceis between 0.04 square centimeters and 0.08 square centimeters in size.